package com.lllll.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.lllll.reggie.common.R;
import com.lllll.reggie.common.utils.BaseContextUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录的过滤器
 */
// urlPatterns说明拦截哪些请求
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    // 路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        // 1获取本次请求的uri
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}", requestURI);

        // 定义不需要处理的请求路径
        String[] urls = new String[]{
                "/common/upload",
                "/common/download",
                "/employee/login",  // 登录
                "/employee/logout", // 退出
                "/backend/**",  // 静态页面
                "front/**",     // 移动端

        };

        // 2判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        // 3如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求{}不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        // 4判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContextUtils.setCurrentId(empId);

            filterChain.doFilter(request, response);
            return;
        }
        log.info("用户未登录");
        // 5如果未登录则返回未登录结果, 通过输出六方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));

    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     *
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
